Nature’s Biggest Explosions: Past, Present, and Future Edo Berger Harvard University Why Study Cosmic Explosions? Why Study Cosmic Explosions? Why Study Cosmic Explosions? Why Study Cosmic Explosions? Why Study Cosmic Explosions? The Past About 10 “guest stars” have been mentioned in historical records, spanning from 185 to 1604 AD. All were observed with the naked eye (first telescope was built in 1608 AD). “Throughout all past time, according to the records handed down from generation to generation, nothing is observed to have changed either in the whole of the outermost heaven or in any of its proper parts.” Aristotle, De caelo (On the Heavens), 350 BC SN 185 In 185 AD Chinese records mark the appearance of a “guest star” which remained visible for 8 months and did not move like a planet or a comet. This is the oldest record of a supernova. “In the 2nd year of the epoch Zhongping, the 10th month, on the day Kwei Hae, a strange star appeared in the middle of Nan Mun … In the 6th month of the succeeding year it disappeared.” SN 1006 On April 1006 records from Europe, the Middle East, and Asia mark the appearance of the brightest “guest star” ever seen: bright as a quarter moon and visible during the day. It remained visible for almost 2 years. “…spectacle was a large circular body, 2½ to 3 times as large as Venus. The sky was shining because of its light. The intensity of its light was a little more than the light of the Moon when one-quarter illuminated" SN 1054 On July 4, 1054 AD records from the Middle East and Asia (and potentially North America) mark the appearance of a bright “guest star”; as bright as a 1/16 moon and remained visible for 2 years. Chaco Canyon, AZ SN 1054? SN 1006? Halley’s Comet (1066)? SN 1572: Tycho’s Supernova In November 1572 a new “guest star” was extensively studied by Tycho Brahe, and published in the book “Concerning the Star, new and never before seen in the life or memory of anyone”. SN 1572: Tycho’s Supernova In November 1572 a new “guest star” was extensively studied by Tycho Brahe, and published in the book “Concerning the Star, new and never before seen in the life or memory of anyone”. SN 1572: Tycho’s Supernova In November 1572 a new “guest star” was extensively studied by Tycho Brahe, and published in the book “Concerning the Star, new and never before seen in the life or memory of anyone”. SN 1604: Kepler’s Supernova In October 1604 the last “guest star” recorded in the Milky Way was observed; published by Johannes Kepler in the book “On the new star in Ophiuchus's foot”. SN 1604: Kepler’s Supernova In October 1604 the last “guest star” recorded in the Milky Way was observed; published by Johannes Kepler in the book “On the new star in Ophiuchus's foot”. SN 1604: Kepler’s Supernova In October 1604 the last “guest star” recorded in the Milky Way was observed; published by Johannes Kepler in the book “On the new star in Ophiuchus's foot”. Where Are They Now? Where Are They Now? SN 185 SN 1006 SN 1054: Crab Tycho's SN Kepler’s SN Any Recent Supernovae in Milky Way? Cassiopeia A (~1670) G1.9+0.3 (~1900) Neither supernova was seen on Earth due to obscuration of the light by dust The Present The modern approach utilizes telescopes to find and study supernovae in other galaxies. It has led to the realization that not all supernovae are the same. The First Supernova Outside the Milky Way In August 1885 a “new star” was discovered in the Andromeda “nebula” using telescopes. In 1917 it was shown that Andromeda was a separate galaxy and therefore this event was a supernova. It remains the only supernova seen in Andromeda. The First Supernova Outside the Milky Way In August 1885 a “new star” was discovered in the Andromeda “nebula” using telescopes. In 1917 it was shown that Andromeda was a separate galaxy and therefore this event was a supernova. It remains the only supernova seen in Andromeda. Naked eye limit The First Supernova Outside the Milky Way In August 1885 a “new star” was discovered in the Andromeda “nebula” using telescopes. In 1917 it was shown that Andromeda was a separate galaxy and therefore this event was a supernova. It remains the only supernova seen in Andromeda. Naked eye limit Supernovae Become a Class of Objects In 1934 Fritz Zwicky and Walter Baade coined the term super-novae. Extremely rare (1 per century per galaxy) and powerful (billions of times the power output of the Sun = total power output of the Sun in its life). In the 1930s Zwicky and Baade began a dedicated search for supernovae by taking images of galaxies and comparing them to old images to look for “new stars”. In the 1930s Zwicky and Baade began a dedicated search for supernovae by taking images of galaxies and comparing them to old images to look for “new stars”. Spot the Supernova Before During Spot the Supernova Before During SN2014J: Discovered during an undergraduate training session at University of London Observatory! SN2014J: Discovered during an undergraduate training session at University of London Observatory! Many Supernovae… Many Supernovae… Many Supernovae… Many Supernovae… Many Supernovae… 2014: 1950 supernovae 2015: 3400 supernovae 2016: 7000 supernovae 2017: 3200 supernovae … But Some are Very Special On February 24, 1987 Oscar Duhalde (telescope operator at Las Campanas Observatory) spotted a supernova in the Large Magellanic Cloud with the naked eye − the first since 1604! … But Some are Very Special On February 24, 1987 Oscar Duhalde (telescope operator at Las Campanas Observatory) spotted a supernova in the Large Magellanic Cloud with the naked eye − the first since 1604! … But Some are Very Special SN1987A has provided us an unprecedented view in the age of modern astronomy. It is still an object of intense study today. … But Some are Very Special SN1987A has provided us an unprecedented view in the age of modern astronomy. It is still an object of intense study today. … But Some are Very Special SN1987A has provided us an unprecedented view in the age of modern astronomy. It is still an object of intense study today. … But Some are Very Special … But Some are Very Special Different Types of Supernovae In 1941 Rudolph Minkowski obtained the first spectra and categorized supernovae into two classes: Type I (no hydrogen) and Type II (hydrogen). Type I are homogeneous, but Type II are heterogeneous. Different Types of Supernovae In 1941 Rudolph Minkowski obtained the first spectra and categorized supernovae into two classes: Type I (no hydrogen) and Type II (hydrogen). Type I are homogeneous, but Type II are heterogeneous. Type I Type II Different Types of Supernovae Different Types of Supernovae What Types Were the Historic SNe? SN1006 (Ia) SN1054 (II) Tycho's SN (Ia) Kepler’s SN (Ia) Cassiopeia A (IIb) G1.9+0.3 (Ia) So What Types of Stars Make Supernovae? So What Types of Stars Make Supernovae? Supernovae from Massive Stars: Type II Supernovae from Massive Stars: Type II What’s Left Behind? Neutron Star Black Hole Supernovae from White Dwarfs: Type Ia Supernovae from White Dwarfs: Type Ia Supernovae from White Dwarfs: Type Ia The Future The Large Synoptic Survey Telescope will find millions of supernovae, and discover new rare supernovae. Next- generation 30-meter telescopes will revolutionize our understanding of the explosion physics. New Types of Supernovae? New Types of Supernovae? New Types of Supernovae? New energy sources? The most massive stars? The First Supernovae? The “Dark Ages” ? Large Synoptic Survey Telescope Large Synoptic Survey Telescope Large Synoptic Survey Telescope Large Synoptic Survey Telescope Large Synoptic Survey Telescope Large Synoptic Survey Telescope The Giant Magellan Telescope “Throughout all past time, according to the records handed down from generation to generation, nothing is observed to have changed either in the whole of the outermost heaven or in any of its proper parts.” Aristotle, De caelo (On the Heavens), 350 BC “Throughout all past time, according to the records handed down from generation to generation, nothing is observed to have changed either in the whole of the outermost heaven or in any of its proper parts.” Aristotle, De caelo (On the Heavens), 350 BC A Dynamic Universe Teeming with Explosions A Dynamic Universe Teeming with Explosions.